Amusement devices which provide a game based on a random or pseudo-random number are known. For example, U.S. Pat. No. 4,240,365 (Brown) teaches an electronic slot machine. This apparatus includes a pseudo-random number generator which cooperates with a central processing unit to determine which of several objects will win a game. The slot machine shown by Brown employs a display similar to that of a mechanical slot machine so as to simulate the mechanical machine. The pseudo-random number generator is commercially available and is programmed by its manufacturer to provide a fixed payout ratio.
U.S. Pat. No. 4,373,723 (Brown et al.) shows an amusement device wherein horses or other objects traverse a path during the game. Each of the horses is powered by an electric motor, and an electronic control unit provides drive signals for each of the electric motors. A program card contains payout information, and this card may be replaced to vary the payout odds. Also, a stepper is provided to alter the odds in discrete steps.
It is also known to vary selected odds of a payout schedule during the early term of the operation of a machine. The owner, thus, will not suffer a large loss soon after installation of the machine. These machines are typically illegal since the alteration of the odds is not displayed.